Along with skeletal muscles, it may be important to monitor heart function in patients with spinal muscular atrophy (SMA). These are the findings from a study conducted by Nationwide Children's Hospital and published online ahead of print in Human Molecular Genetics. This is the first study to report cardiac dysfunction in mouse models of SMA.
SMA is a debilitating neurological disease that leads to wasting away of muscles throughout the body. Historically, scientists and physicians believed that SMA only affected skeletal muscles; however, new data suggests that this genetic disease may also impact the heart.
"A few studies regarding SMA patients have implicated the involvement of the cardiovascular and the autonomic nervous system," said the study's co-author Brian Kaspar, PhD, principal investigator in the Center for Gene Therapy at The Research Institute at Nationwide Children's Hospital. "However, there have been few to no highly powered and controlled studies to determine how common these cardiovascular anomalies are in these patients."
The reports of altered blood flow and slowed heart rate in some SMA patients prompted Kaspar's team to examine whether a cardiac deficit is present in a mouse model of severe SMA, developed by Arthur Burghes, PhD, professor of Molecular and Cellular Biochemistry at The Ohio State University College of Medicine, which is routinely used for drug and therapeutic-based screening.
They analyzed heart structure of the SMA mice compared with normal mice, and found that there were significant structural changes occurring in the heart of the SMA mice, along with severely impaired left-ventricular function. SMA mice also had significantly lower heart rates. After examining the underlying structure of the mouse heart cells they found it similar to the cellular structure of a heart biopsy from patient with type 3 SMA.
Kaspar's team recently developed a gene therapy approach shown to successfully deliver the missing SMN protein to SMA mice and improve neuromuscular function. Next, the team studied whether the discovered heart defects could be corrected by this gene delivery treatment. Results showed that restoring SMN levels completely restored heart rates and prevented the early development of dilated cardiomyopathy.
Pam Lucchesi, PhD, director of the Center for Cardiovascular and Pulmonary Research at The Research Institute at Nationwide Children's Hospital and study co-author, says it is still not clear which mechanisms are fully responsible for the heart deficits seen in the SMA mice, but data suggests that neuronal, autonomic and developmental components all may play a role.
"Our gene delivery strategy has unique advantages in that it targets neurons within the central and peripheral nervous system as well as the cardiac tissues," said Lucchesi, also a faculty member at The Ohio State University College of Medicine.
More research is needed to determine whether the cardiac deficits are unique to the mouse or whether SMA patient of various severities have or will develop similar issues. Still, Kaspar, also on the faculty at The Ohio State University College of Medicine, says clinicians should be acutely aware of potential heart dysfunction in a subset of SMA patients.
"Increasing reports of autonomic dysfunction together with our current findings warrant increased attention to the cardiac status of SMA patients, and potentially highlights the need to investigate cardiac interventions alongside neuromuscular treatments," said Kaspar.
This research was funded in part by a 2009 American Recovery & Reinvestment Act grant from the National Institutes of Health.
Erin Pope | EurekAlert!
Complementing conventional antibiotics
24.05.2018 | Goethe-Universität Frankfurt am Main
Building a brain, cell by cell: Researchers make a mini neuron network (of two)
23.05.2018 | Institute of Industrial Science, The University of Tokyo
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
24.05.2018 | Ecology, The Environment and Conservation
24.05.2018 | Medical Engineering
24.05.2018 | Physics and Astronomy